[kh99]

Originally Posted by vgevolution

Is it possible, via the plug-in system, to override built-in vbulletin functions, like those in functions.php?

No. Well, maybe. As it says in the php manual, "PHP does not support function overloading, nor is it possible to undefine or redefine previously-declared functions." However, there is an add-on that apparently allows you to do that called "runkit", but it doesn't come with PHP by default, you'd have to get it and install it. http://www.php.net/manual/en/book.runkit.php

Of course another option would be to make a plugin with your additional function and your version of fetch_censor_text(). Then when you update vbulletin, all you'd have to do is comment out or rename the existing fetch_censor_text().